Electric-motor sysyem.



No. 773,120. PATENTED OCT. 25, 1.904.

' A. F. CHRISTMAS.

ELECTRIC MOTOR SYSTEM.

APPLICATION FILED DEC. 2, 1903 NO MODEL.

WITNESSES. INVENTOR. 9 6Q- MC/ [ll m mm UNITED STATES Patented October25, 1904.

PATENT OFFICE.

ADOLPH F. CHRISTMAS, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR OF TVVO-THIRDSTO FRANK R. M FEATTERS, OF WILKINSBURG, PENN- SYLVANIA.

ELECTRIC-MOTOR SYSTEM.

SPECIFICATION forming part of Letters Patent No. 773,120, dated October25, 1904.

' Application filed December 2, 1903. Serial No. 188,518. (No model.) i

To all whom it 777/(LZ/ concern.-

Be it known that I, ADoLPH F. CHRISTMAS, a resident of Pittsburg, in thecounty of Allegheny and State of Pennsylvania, have invented a new anduseful Improvement in Electric-Motor Systems; and I do hereby declarethe following to be a full,clear, and exact description thereof.

My invention relates to electric-motor systems, and more especially to asystem for operating reciprocating electric motors provided with aplurality of coils.

One object of my invention is to provide such a system wherein areciprocating motor having two coils and of simple design may beemployed and whereby the circuit Will be broken and made momentarily andalternately through the two coils, so that heating of the motor isavoided and a high efiiciency developed.

A further object of the invention is to provide such amotor systemwherein the making of the circuit alternately through the two coils ofthe motor will be in synchronism with the period of oscillation of thearmature of the motor.

Afurther object of my invention is to provide such a system wherein themotor is cushioned and aided by the expansive forces of air which isautomatically compressed in the operation of the motor.

The accompanying drawingshows a diagram of the system, the motor and thecircuit maker and breaker being shown in section.

My invention is intended to operate With reciprocating motors providedwith two coils. Such a motor is shown in the drawing and has beenillustrated as a reciprocating hammer. This motor is provided with asuitable frame or casing 1, having therein the coils 2 and 3. In thesecoils is the sleeve or bobbin 4:, in which reciprocates the core orarmature 5, which latter performs the desired work-- such, for instance,as operating a tool 6. The active or Working stroke of the core 5 issecured by the energization of the coil 2, and its idle or rearwardstroke is secured by the energization of the coil 3. The inner end ofthe sleeve 4 is tightly closed, as by means of a head 7, and the corefits said sleeve closely, so that in its idle or backward movement itwill compress air between its inner end and the head 7 which air notonly acts as a cushion, but also by its expansive force starts the coreon its outward or active stroke, thus aiding the coil 2 and increasingthe strength of the blow. In order that this air-space may not act bysuction to retard the core 5 in its outward movement, a suitableair-vent is provided in such relation that it will be uncovered by theinner end of the core 5 when the latter approaches the limit of itsoutward move ment. This duct is shown at 8 as passing through thepartition 9 between the two coils 2 and 3 and communicating with agroove 10 in the inner face of the sleeve 1, which extends to therequired distance to be uncovered by the core at the proper time.

The coils 2 and 3 are energized alternately and only momentarily, thusgettinga strong magnetic pull on the core and at the same timepreventing the heating of the coils and motor, as would be the case ifthe current were switched directly from one coil to the other withoutany appreciable interval of time between the same.

For breaking the circuit and making it alternately through the two coilsI make use of a circuit-interrupting device, which is specificallydescribed and claimed in my application, Serial No. 183,519, filedDecember 2,

1903, and which comprises a rotary body 12, preferably a cylindricalmetallic tube having heads 13 of suitable insulating material andsuitably mounted to rotate in standards or bearings let. In the chamber15 is a body of mercury 16, which, however, only partially fills thesame. Projecting through the heads 13 are circuit terminals or fingersl7 and 18, which for simplicity of construction are extended to form thetrunnions on which the body is rotated. Secured to each of theseterminals outside of the insulated heads are metallic plates 19, againstwhich bear brushes and 21, respectively. Bearing against the outer faceof the cylindrical body 12 is another brush 22. The two fingers 17 and18 are oppositely arranged, as shown, and in the rotation of the bodythe mercury will remain stationary, and these fingers will alternatelysweep through or come in contact with said mercury, thus establishing anelectric path from the brush 22 through the mercury and alternately tothe finger 17 and brush 20 and to the finger 18 and brush 21. Thebrushes 20 and 21 are connected electrically to binding-posts 23 and 2The motor and circuit-interrupter described are connected in a suitablesystem having a generator 25 and a positive main 26 and negative main27. The positive main is connected to the brush 22, and therefore isalways in electric connection with the mer cury in the chamber of thecircuit-breaker. The negative main 27 is connected to the two coils 2and 3 of the motor, being common to said coils. The coil 2 of the motoris connected by awire 28 to, the brush 20 of the circuit-breaker, whilethe coil 3 of the motor is connected by a wire 29 to the brush 21 of thecircuit-breaker.

The circuit-breaker may be rotated in any suitable way--such, forinstance, as by attaching a handle or crank to one of the trunnionsthereof. Preferably, however, one of the trunnions will be provided witha pulley 30, which will be driven by means of a belt 31 from anysuitable source of power, such as a counter-shaft in a factory or otherconvenient source. Preferably, however, said circuit-breaker will bedriven from an electric motor 32, bridged across the mains 26 and 27 andhaving its shaft provided with a pulley 33 for receiving the belt 31.

A suitable starting and stoppingdevice will be provided on or inproximity to the motor, and when the latter is used for a reciprocat inghammer, such as shown, this starting and stopping device canconveniently take the form of a switch-blade 35, cooperating withterminals 36, a suitable lever 37 being provided for closing the switchwhen the tool is grasped by the operator and a spring 38 being providedfor opening said switch as soon as the tool is released, all asdescribed and claimed in my application, Serial No. 183,520, filedDecember 2, 1903.

In the operation of this motor system the current coming from thepositive brush of the generator will pass to the brush 22 and throughthe metallic casing 12 to the mercury contained therein, the circuitinterrupter will be rotated, and the fingers 17 and 18 will alternatelycome in contact with the mercury, thus alternately directing the currentfrom the mercury to the brush 20 and coil 2 of the motor or to the brush21 and coil 3 of the motor, thus causing alternate energizations ofthese coils. Inasmuch as the fingers 17 and 18 are comparatively narrow,they will be in contact with the mercury only a short interval of timecompared to the period elapsing between the time when one of saidlingers leaves the mercury and the other comes in contact therewith. Asa consequence the coils 2 and 3 of the motor are only momentarilyenergized, getting thereby a strong magnetic pull on the core and at thesame time preventing the coils and motor from heating, as would be thecase if the current were continued through each coil until it wasswitched into the next coil. The rotation of the circuit-breaker will betimed so as to be in synchronism with the period of oscillation of thecore 5 of the motor. Furthermore, the core of the motor fitting closely,as it does, in the sleeve 4 will in its backward or idle stroke compressair between itself and the head 7, which compressed air by its expansiveforce starts the core on its forward or active stroke and reinforces themagnetic pull caused by the energization of the coil 2, thus increasingthe strength of the blow.

It will thus be seen that in my improved motor system the magnetic pullof the coil is reinforced by the compressed air stored on the idlemovement of the core. Furthermore, by reason of maintaining the currentthrough the motor-coils for only a short period of time the expenditureof energy for the work obtained is very small. The circuit-interrupteris such that it can be made to act in exact synchronism with the motor,and it is not detrin'ientally affected by the arcs which occur when thecurrent is interrupted, as such arcs will merely expend themselves involatilizing a portion of the mercury; but as the latter is contained ina tight casing it will again condense and seek the main body of mercury.This rotating circuit-breaker will automatically make and break thecircuit to the motor-coils as long as the circuit is closed at themotor. hen this circuit, however, is open, the circuit-breaker willstill continue to rotate, but only idly, and as it requires practicallyno power to rotate it no appreciable loss of energy occurs.

My motor system will operate with either a direct or alternatingcurrent.

hat I claim is 1. In an electric-motor system, the combination with areciprocating motor having a plurality of coils, circuits thereto, and acircuitinterrupter and changer arranged to break the circuits and makethem alternately through said coils, said circuit interrupter andchanger being arranged to allow a long time interval between thebreaking of the circuit and the succeeding making thereof.

2. In an electric-motor system, the combination with a reciprocatingmotor having a plurality of coils, circuits thereto, and a circuitinterrupter and changer arranged to break the circuits and make themmomentarily and alternately through said coils.

3. In an electric-motor system, the combination with a reciprocatingmotor, a plurality of coils therefor, a reciprocating armaturecooperating with said coils, circuits to said coils, and a circuitinterrupter and changer arranged to break said circuits and make thesame alternately through said coils and in synchronism with the periodof oscillation of the armature, said circuit interrupter and changerbeing arranged to allow a long time interval between the breaking of thecircuit and the succeeding making thereof.

4. In an electric-motor system, the combination with a reciprocatingmotor, a plurality of coils therefor, a reciprocating armaturecooperating with said coils, circuits for said coils, and a circuitinterrupter and changer arranged to break the circuits and make themmomentarily and alternately through said coils and insynchronism withthe period of oscillation of the armature.

5. In an electric-motor system, the combination with a plurality ofcoils, a sleeve'therefor closed at one end, a reciprocating core in saidsleeve and closely fitting the same and acting with the closed end ofthe sleeve to form an. air-cylinder, circuits to said coils, and acircuit interrupter and changer arranged to break the circuits and makethem momentarily and alternately through said coils.

6. In an electric-motor system, the combination With a plurality ofcoils, a sleeve therein closed at one end, a reciprocating core in saidsleeve and closely fitting the same and acting with the closed end ofthe sleeve to form an air-cylinder, circuits to said coils, and atime-interval circuit interrupter and changer arranged to break saidcircuits and make them alternately and momentarily through said coilsand in synchronis'm with the period of oscillation of the armature.

7. In an electric-motor system, the combination with a reciprocatingmotor having a plurality of coils, circuits therefor, and a rotarymercury circuit maker and breaker in said circuits arranged to breaksaid circuits and make them alternately through said coils 8. In anelectric-motor system, the combination with a plurality of coils, ofcircuits therefor, a rotary circuit-interrupter having a chamberpartially filled with mercury, a positive terminal in constantconnection with said mercury, and oppositely-arranged terminalsprojecting into said chamber and arranged to alternately and momentarilydip into the mercury in the rotation of the body, and independentconnections from said terminals to the coils of the motor. 7

9. In an electric-motor system, the combination with a reciprocatingmotor provided with two coils, a source of energy, a rotary circuitbreaker comprising a chamber partially filled with mercury, a mainconnecting the positive brush of the source of energy with said mercury,two oppositely-arranged contacts cooperating With the mercury andarranged in the rotation of the body to, alternately contact With saidmercury, connections between each of said contacts and one of the coilsof the motor, a main from said coils to the negative pole of the sourceof energy, a motor bridged across the mains, and connections betweensaid motor and the rotary circuit-breaker.

In testimony whereof L the said ADoLrH F. CHRISTMAS, have hereunto setmy hand.

ADOLPH F. CHRISTMAS.

Witnesses:

F. W. WINTER, ROBERT (J. TOTTEN.

